1. Technical Field
The present disclosure relates to reciprocating hammers and, more specifically, to a reciprocating hammer with downward thrust assist.
2. Description of the Related Art
Pile driver mechanisms are used to drive piles (i.e., poles) into soil or other earthen material, such as to provide foundation support for buildings or other structures. Traditional pile drivers have a ram constrained by a guide structure so that the ram is able to freely slide up and down along a vertical axis. In use, the ram is aligned with a pile to be driven, raised (i.e., by hydraulics or other energy source), then released so that the ram drops through a distance determined by the guide structure and impacts the pile, delivering its kinetic energy to drive the pile into the ground.
In this raise/release modality for pile driving, there are two determinates of impact strength: the weight of the ram and the length of its stroke from the release point to the impact point. For example, a 10,000 pound weight dropped a distance of three feet upon a pile below theoretically yields up to 30,000 foot-pounds of impact force, it being understood that the actual impact force will be marginally lower to account for air resistance, friction, and other mechanical inefficiencies. In order to increase this 30,000 foot-pound theoretical maximum, the weight of the pile driver ram and/or the stroke length of the guide structure must be increased.
Pile driving mechanisms may be positioned and actuated by industrial machinery with the weight carrying capacity and vertical reach sufficient for a particular application. For example, excavator machines having articulating arms may have a pile driving mechanism attached at the distal end of such an articulating arm, which raises the mechanism to a desired height and positions the mechanism over a pile to be driven. In other instances, mobile or stationary cranes may be used in a similar fashion, with pile driving mechanisms attached to or suspended from the end of the telescoping arm of the crane. However, the weight capacity of the machine to which the pile driving assembly is mounted limits the maximum weight of the pile driving ram, while the height capacity of the machine's pile driving mechanism mount limits the overall height of the mechanism and therefore the possible stroke through which the ram may be dropped.